Scientist Nina and her young experimenters discover the amazing ways that things can change and react in our everyday world. Nina investigates why sugar is bad for our teeth with the help of Bud, her taste neuron. Experimenters Holly, Nidhi and Slaley visit Nina in her lab, Using their senses, they discover that something called plaque forms on teeth. Nina does an experiment to prove that when plaque mixes with sugar, an acid is formed. Then they all visit a print studio in Newcastle and see an acid used to make a picture of Bud. They see that some acids can eat away at other things, even metal. Finally, back in the lab, the experimenters use vinegar and fake teeth made from chalk to show how acid can damage teeth.